The evaluation of DNA aptamer monolayers on silicon surface for the promotion of cell-surface interaction

Abstract

DNA aptamers are very specific towards biological targets and are useful in many biosensor applications. However, there had been little reports that systematically examined the potential of DNA aptamers as surface thin film for promoting cell-surface adhesion. In this work, three aptamers (IDA, NC3S and SYL3C) were grafted on silicon surface and were only selective towards epithelial cell type. To better demonstrate this selectivity, click chemistry on underlying PEG layer was performed to attach these DNA aptamers on the surfaces so as to discourage non-specific cell attachment. The physicochemical properties of the surfaces were examined via XPS, AFM, FTIR and contact angle goniometry. A range of different cell types (MDA-MB 231, A549, MES-SA, N2A and HaCaT) were incubated to these surfaces and their viability, morphology and focal adhesion protein expression levels were quantified after a period of 24 h. From our observations, we had shown that NC3S and SYL3C can actively promote cell adhesion while integrin targeting IDA did not help to improve the outcomes of cell-surface interaction. Moreover, aptamer functionalized surfaces were observed to be only favorably towards epithelial cell types and our current findings here had help shed light on DNA aptamer as potential bioactive thin films that are cell type selective.